Risk Factors of Childhood Obesity in Manitoba: A Population-Based Study BN Yu MD Ph.D Manitoba Health University of Manitoba Presenting at American Public Health Association Monday 05 November 2007

Collaborators JLP Protudjer MSc. K Anderson MSc., RD P Fieldhouse Ph.D

Background Childhood obesity: Public health issue Associated with substantial costs1 Obesity prevalence tripled in Canada between 1978/9 (3%) and 2004 (9%)2 Overweight/obesity prevalence is significantly higher in Manitoba (31%) than Canadian average (26%) 2 1Katzmarzyk P. & Janssen I. Can J Appl Physiol. 2004;29(1):90-115. 2 Shields M. Health Reports 2006;17(3):27-42.

Data Source Canadian Community Health Survey 2.2 on Nutrition (CCHS 2.2) Conducted by Statistics Canada in 2004 First survey to provide national, provincial and regional nutrition data in > 30 years 24 hr dietary recall Measured heights and weights General health and chronic conditions

Data Source cont’d Manitoba Health and Healthy Living Purchased additional sample to enhance analysis at sub-provincial level Measured heights and weights for 1172/ 1651 (71%) Manitobans 2-17 years old Computer assisted personal/telephone survey www.gov.mb.ca

Province of Manitoba www.gov.mb.ca

Combined Health Regions

Childhood Obesity Definition Measured body weight and height BMI = body weight (kg) / height (m2) International Obesity Task Force age- and sex-specific cutoffs1 Normal weight Overweight Obese Pregnant females were excluded 1Cole T. et al. British Med J 2000;320:1240.

Measurements Correlates Social Economic Status Healthy Living Food Security Off-Reserve Aboriginal Culture/Racial Origin Combined Health Regions Gender Age group Social Economic Status Highest household education Family income adequacy quartiles Healthy Living Physical Activity Sedentary Activity Fruit/vegetable consumption

Household Food Insecurity Definition: “Limited or uncertain availability of nutritionally adequate and safe foods or limited or uncertain ability to acquire acceptable foods in socially acceptable ways” (Anderson, 1990). USDA standardized instrument (18 questions) which produced a summarized index variable on Household Food Security: Food secure Food insecure without hunger Food insecure with moderate hunger Food insecure with severe hunger

Statistical Analysis SAS 9.1 for Windows Descriptive Statistics Logistic regression analyses Two estimation procedures as per Statistics Canada1 Appropriate statistical weight Design-based variance estimation via Bootstrap 1Bailie L. et al. Statistics Canada 2002; Ottawa, ON.

Sample Distribution Table 1. Description of the Population by Age Group and Gender   Boys Girls Age Group n % 2-5 200 23.8 188 23.2 6-11 279 33.2 274 33.8 12-17 361 43.0 349 Total 840 100.0 811 Total both boys and girls=1651

Overall Prevalence of Overweight/Obesity in Manitoba Children Age 2 – 17 Years

Figure 1. Prevalence of Weight Categories in Manitoba Children (age 2-17)

Figure 2. Prevalence of Overweight/ Obesity in Manitoba Children by Age Group and Gender

Figure 3. Prevalence of Overweight/ Obesity Manitoba Children (age 2-17) by Off-Reserve Aboriginal Status

Figure 4. Prevalence of Overweight/ Obesity in Manitoba Children (age 2-17) by Total Family Income

Figure 5. Prevalence of Overweight/ Obesity in Manitoba Children (age 2-17) by Highest Level of Parental Education

Figure 6. Prevalence of Overweight/ Obesity in Manitoba Children (age 2-17) by Food Insecurity

Table 2. Multivariable Logistic Regression Analyses on Overweight/Obesity Risk Factors in Manitoba Boys (age 2-17) Risk Factor Odds Ratio 95% Confidence Interval p-value Age Group 1.52 1.05-2.19 0.03 Food Insecurity 2.09 1.42-4.19 0.04 Parental Education 0.91 0.61-1.36 NS Income Adequacy 0.87 0.62-1.22 Aboriginal Origin 1.18 0.42-3.32

Table 3. Multivariable Logistic Regression Analyses on Overweight/Obesity Risk Factors in Manitoba Girls (age 2-17) Risk Factor Odds Ratio 95% Confidence Interval p-value Age Group 1.27 0.94-1.72 NS Food Insecurity 1.65 0.79-3.49 Parental Education 0.58 0.36-0.96 0.03 Income Adequacy 1.03 0.82-1.21 Aboriginal Origin 1.44 0.49-4.28

Geographic Locations & Overweight/Obesity By Age Group and Gender

Figure 7. Prevalence of Overweight/ Obesity in Manitoba Children (age 2-11) by Gender & Combined Health Regions

Figure 8. Prevalence of Overweight/Obesity in Manitoba Adolescents (age 12-17) by Combined Health Regions

Table 4. Multivariable Logistic Regression Analyses on Overweight/Obesity Risk Factors in Manitoba Boys (age 2-11) Risk Factor Odds Ratio 95% Confidence Interval p-value Parental Education 0.97 0.06-2.43 NS Income Adequacy 0.88 0.59-1.32 Region of Residence1 1.46 1.10-1.94 0.01 Aboriginal Origin 2.30 0.74-7.12 1Reference Region=South western Manitoba

Table 5. Multivariable Logistic Regression Analyses on Overweight/Obesity Risk Factors in Manitoba Girls (age 2-11) Risk Factor Odds Ratio 95% Confidence Interval p-value Parental Education 0.62 0.36-1.08 NS Income Adequacy 0.76 0.52-1.12 Region of Residence1 1.10 0.83-1.47 Aboriginal Origin 2.00 0.70-5.76 1Reference Region=South western Manitoba

Healthy Living & Overweight/Obesity In Adolescents

Figure 9. Prevalence of Overweight/Obesity in Manitoba Adolescents (age 12-17) by Daily Physical Activity

Figure 10. Prevalence of Overweight/Obesity in Manitoba Adolescents (age 12-17) by Weekly Sedentary Activity

Figure 11. Prevalence of Overweight/Obesity in Manitoba Adolescents (age 12-17) by Daily Fruit/Vegetable Consumption

Table 6. Multivariable Logistic Regression Analyses on Overweight/Obesity Risk Factors in Manitoba Boys (age 12-17) Risk Factor Odds Ratio 95% Confidence Interval p-value Parental Education 0.83 0.60-1.22 NS Regular Physical Activity1 0.23 0.05-1.09 0.06 Sedentary Activity2 1.35 0.86-2.13 ≥ 5 Fruits/ Veg per Day3 1.10 0.32-3.83 1 Regular and occasional physical activities lasting > 15 minutes per time. 2Sedentary behaviour ≤ 19 hours or ≥ 20 hours per week in past 3 months. 3 Consumption of fruits and vegetables ≥5 times per day.

Table 7. Multivariable Logistic Regression Analyses on Overweight/Obesity Risk Factors in Manitoba Girls (age 12-17) Risk Factor Odds Ratio 95% Confidence Interval p-value Parental Education 0.67 0.43-1.02 0.06 Regular Physical Activity1 0.91 0.24-3.47 NS Sedentary Activity2 1.45 1.04-2.02 0.03 ≥ 5 Fruits/ Veg per Day3 0.38 0.14-1.02 1 Regular and occasional physical activities lasting > 15 minutes per time. 2Sedentary behaviour ≤ 19 hours or ≥ 20 hours per week in past 3 months. 3 Consumption of fruits and vegetables ≥5 times per day.

Summary: Overall Prevalence Nearly 1/3 of Manitoba children aged 2-17 (31%) are overweight or obese. Or, nearly ¼ of Manitoba children (22%) are overweight and almost one in ten Manitoba children (9%) are obese. The prevalence of overweight/ obesity in Manitoba children increases with age, from 23% for children 2-5 years old, to 29% for 6-11 year olds and to 35% for 12-17 year olds.

Summary: Social Economic Status The prevalence of overweight/ obesity decreases as parental education and household income increases. Over 40% of children from food insecure households are overweight/ obese. Gender: Boys from food insecure households are twice as likely to be overweight/ obese as compared to boys from food secure homes. Parental education significantly affects the prevalence of overweight/obesity in girls, but not in boys.

Summary: Geographic Location 2 – 11 Age Group: Boys who live in south eastern and central Manitoba have relatively lower risk for being overweight or obese. 12 – 17 Age Group: Data showed a north to south decrease in the prevalence of overweight/obesity among Manitoba adolescents, but this trend did not reach statistical significance due to small sample size.

Summary: Healthy Living in Adolescents Boys: Regular physical activity reduces the risk of being overweight/obese. Girls: Being more sedentary increases the risk of being overweight/obese; Consuming fruits and vegetables more than 5 times per day has protective effect on healthy weight.

Conclusion: High Risk Sub-populations Boys living in food insecure households. Girls whose parents had not completed high school. Adolescent girls who are more sedentary and/or consume fruits and vegetables less than 5 times per day. Adolescent boys who are infrequently physically active.

Conclusion: Policy Implications The identification of risk factors among specific populations is beneficial in tailoring public health policies and programs for prevention/ intervention of childhood obesity.

Strengths Measured heights and weights Sub-provincial (regional) analyses Associations identified between obesity and: Gender Age Food Insecurity

Limitations Many self- or proxy-reported data Cross-sectional Some small sample sizes Physical and sedentary modules may not fully represent children’s habits Vegetable, fruit and juice consumption based on frequency, not quantity

Future Directions Increase awareness/ promotion of obesity prevention Media, language, style of approach Strategies/ policies Targeting high-risk groups Addressing health determinants Creating healthy environments to support healthy living

Acknowledgements Manitoba Health & Healthy Living Ms. Kelly McQuillen Ms. Dale Brownlee Dr. Greg Hammond Dr. Mike Routledge Dr. Patricia Caetano Mr. Rolf Puchtinger Winnipeg Regional Health Authority Dr. Mike Moffat Other Dept of the Government of Manitoba Dr. Chris Green Ms. Leanne Boyd

Manitoba Government Initiatives for Active Living, Chronic Disease Prevention and Healthy Eating Chronic Disease Prevention Initiative Develop community-led activities to address chronic disease risk factors in 60 communities Healthy Schools Promote healthy lifestyles and activities that promote lifelong wellness Food in Schools Help school communities develop and implement nutrition policies In-Motion Help Manitobans make physical activity part of their daily lives for health and enjoyment Healthy Child Manitoba Works with families to support their children within strong communities to help children reach their potential Northern Healthy Foods Initiative Works with northern communities to develop community gardens, create greenhouses, develop food focused business and nutrition awareness

Summary of Regional Policies, Programs and Activities Related to Healthy Weights and Obesity Pre- & postnatal nutrition education for parents Family-focused activities Community-based nutrition activities Preschool literacy- & healthful eating programs Day care menu reviews Wellness fairs for parents of preschoolers Nutrition counseling by dietitians School partnerships Recreation centre partnerships Participate in health professional and community networks to facilitate partnerships & planning